Washington (CNN) -- A rapidly evolving terrorist threat will continue to dominate U.S. security concerns over the course of the next year, top intelligence officials told members of Congress on Thursday.
While al Qaeda and its allies have been dealt a series of setbacks by America and its allies, they are having success finding new recruits in the United States and Europe, the officials warned. They are also tied to a troubling insurgency in Pakistan that poses a danger not only to the government in Islamabad but also to U.S. troops in the region.
The officials warned that a congressional failure to renew key provisions of the Patriot Act could cripple vital intelligence-gathering operations. In addition, they noted the growing importance of cybersecurity to the United States.
The warnings were delivered to members of the House Permanent Select Committee on Intelligence during the panel's annual threat assessment hearing.
"It is virtually impossible to rank, in terms of long-term importance, the numerous potential threats to U.S. national security," National Intelligence Director James Clapper told members of the committee. "The United States no longer faces -- as in the Cold War -- one dominant threat. Rather, it is the multiplicity and interconnectedness of potential threats, and the actors behind them, that constitute our biggest challenge."
Clapper noted that multiple terror plots have been disrupted recently. But while "clear progress (is) being made in some fronts" there are "new challenges arising elsewhere," he said.
The intelligence director noted that the Pakistan-based leadership of al Qaeda "continues to aspire to spectacular attacks" against the West. While America and its allies have "weakened much of al Qaeda's core capabilities," there are "disturbing instances of self-radicalization among our own citizens."
While homegrown terrorists often lack technical sophistication, they are nevertheless well-positioned to launch damaging attacks, CIA Director Leon Panetta added. Panetta cited the example of the November 2009 massacre at Fort Hood, which left 13 people dead and 32 wounded.
The officials highlighted the continued importance of countering the proliferation of weapons of mass destruction, particularly in regard to Iran and North Korea.
"We see a disturbing confluence of events" relating to an Iranian regime that is increasingly "rigid" and "autocratic," Clapper said. North Korea craves recognition as a nuclear power and therefore still poses a major threat "regionally and beyond."
Counterintelligence threats are also a concern, Clapper noted. While acknowledging the danger posed by foreign intelligence threats, he said disclosures from WikiLeaks "have clearly been very damaging."
On the cyberthreat, Clapper said it is "increasing in size and scope." Panetta went so far as to say, "I think the next Pearl Harbor could very well be a cyberattack."
Representative Jim Langevin, D-Rhode Island, didn't get a direct response to his question about whether the U.S. could stop a major cyberattack against the nation, but he seemed to get the point.
Department of Homeland Security Undersecretary Caryn Wagner haltingly told him, "I would say that the administration is working right now on a comprehensive cybersecurity strategy that I hope will allow us to do that."
Langevin's response, "I think the answer is no."
Both Clapper and Panetta defended U.S. intelligence operations in Egypt, which have been closely scrutinized and criticized for failing to predict the political turmoil engulfing the Mubarak regime.
Accurate information about the situation in Egypt was provided to U.S. officials, Clapper said, but "specific triggers" for incidents that will cause a regime to fall cannot always be accurately predicted, he said.
"We are not clairvoyant," he added.
Panetta noted, however, that a 35-member task force has been established at the CIA to help collect more accurate information on factors such as public opinion and the strength of political opponents in Egypt and elsewhere.
"Our biggest problem is how do we get into the head of somebody" such as Egyptian President Hosni Mubarak, he said.
If a transfer of power in Egypt is "done right," it will help promote stability in the Middle East, Panetta said. But if such a transition goes poorly, it could cause a dangerous destabilization of the region.
Some committee members raised the issue of the role the Muslim Brotherhood might play in any new government. The Brotherhood is the largest and most organized opposition group in Egypt and has a religious and political agenda.
Representative Sue Myrick, R-North Carolina, expressed concern the Islamic group would use the protests for a "power grab."
She added, "The Brotherhood isn't a danger because they are terrorists, but because they push an extremist ideology that causes others to commit acts of terrorism."
When Myrick asked about the Brotherhood's ideology, Clapper made a surprising comment, referring to the Egyptian Muslim Brotherhood as secular.
"The term 'Muslim Brotherhood' is an umbrella term for a variety of movements, in the case of Egypt, a very heterogeneous group, largely secular, which has eschewed violence and has decried al Qaeda as a perversion of Islam. They have pursued social ends, a betterment of the political order in Egypt, et cetera," Clapper told the committee.
The National Intelligence office later issued a statement clarifying Clapper's comments.
"In Egypt, the Muslim Brotherhood makes efforts to work through a political system that has been, under Mubarak's rule, one that is largely secular in its orientation," the statement said. "He is well aware that the Muslim Brotherhood is not a secular organization."